Display devices such as liquid crystal display devices are widely used in various fields. For a liquid crystal display device, it generally comprises display substrates (such as an array substrate and a color film substrate) and a liquid crystal layer arranged between the display substrates. With the development of the display technology, a thin film transistor comprising an oxide semiconductor active layer may be applied in the display substrate. Such a thin film transistor has a relatively high carrier mobility and a relatively low leakage current, therefore it is favorable for achieving integration, thinness and lightness, high image quality and low power consumption of the display device.
However, the oxide semiconductor is generally sensitive to light, particularly ultraviolet light. Therefore, when the thin film transistor comprising an oxide semiconductor active layer is applied in a display substrate such as an array substrate, the property of the oxide semiconductor in the active layer may be easily changed and produce flaws under the irradiation of the ultraviolet light (for example, the ultraviolet light contained in backlight), thereby rendering malfunction of the display substrate and the display device comprising the display substrate.